Tissue protection device for mitral valve membrane cerclage procedure

ABSTRACT

The present invention relates to a tissue protection device for mitral valve cerclage annuloplasty and, more particularly to a tissue protection device for protecting tissues of the body (heart) during mitral valve cerclage annuloplasty that is performed on a mitral valve cerclage patient with mitral regurgitation. The tissue protection device for mitral valve cerclage annuloplasty of the present invention is a hollow cylindrical tube where cerclage sutures (10a, 10b) are inserted, in which a hole (22) is formed at a predetermined portion of the cylindrical tube so that a coronary sinus cerclage suture (10a) inserted in a coronary sinus comes out of the cylindrical tube, and a lower section from the hole is inserted into the tricuspid valve to protect tissues of the tricuspid valve and the ventricular septum.

TECHNICAL FIELD

The present invention relates to a tissue protection device for mitralvalve cerclage annuloplasty and, more particularly to a tissueprotection device for protecting tissues of a body (heart) during mitralvalve cerclage annuloplasty that is performed on a mitral valve cerclagepatient with mitral regurgitation.

BACKGROUND ART

The heart is the center of the human circulatory system that pumps bloodthrough our body. It is a muscle that pumps the blood only in onedirection. In order for the heart to effectively maintain thisunidirectional flow of blood, it must have properly functioning valvesthat prevent back flow through its system, or regurgitation. The heartis divided into four chambers: right and left atrium, and right and leftventricles. The four chambers are connected to the aorta, inferior andsuperior vena cava, pulmonary artery, and pulmonary veins.

The mitral valve (MV) separates left atrium from left ventricle whilethe tricuspid valve (TV) separates right atrium from the rightventricle. The aortic valve (AV) is located between the left ventricleand the aorta while the pulmonary valve (PV) is located between theright ventricle and the pulmonary artery.

Generally, valves should open and close completely with every heart beator contraction. Incomplete opening or closing of the valves causesimproper flow of blood. Valvular diseases are divided into twocategories, regurgitation and stenosis. Regurgitation is a failure of avalve to close completely and stenosis is a failure of a valve to opencompletely.

Mitral valve regurgitation (MVR) is a common cardiac valve disorder thatis caused by incomplete closure of the mitral valve (MV). The MV islocated between the left atrium and the left ventricle. Over time, MVRplaces a burden on the heart and worsens its ability to pump bloodproperly. Such stress on the heart will ultimately lead to heartfailure.

Traditional treatment for worsening MVR requires open heart surgery withsternotomy or thoracotomy with cardiac arrest and cardio-pulmonarybypass. Once the chest is open and access to heart is gained, the MV iseither repaired or replaced using an artificial valve. Although veryeffective, this open-heart procedure is a high risk surgery accompaniedby substantial morbidity and prolonged convalescence. Mortality due tosurgery itself can be as high as 5%. As a result, the procedure often isnot offered to patients who are insufficiently symptomatic to justifythe surgical risk and morbidity, or to patients with substantialco-morbidity. It is reserved only for those with severe symptomatic MVR.This high morbidity rate of open heart surgery has motivated furtherresearch into developing a safer and less risky alternative to repairMV. Much of the research involves use of cardiac catheterization.Recently, the inventor of the present invention presented a thesisregarding “mitral valve cerclage coronary sinus annuloplasty (MVA”showing outstanding results of MVR treatment through applying circularpressure around the mitral annulus (MA). This thesis has been filedthrough PCT as an international patent application (PCT applicationnumber PCT/US2007/023836) and has been published (Internationalpublication number WO2008/060553).

The aforementioned thesis and published patent application disclosed themitral cerclage coronary annuloplasty (MVA) procedure. Brieflyexplained, a catheter is placed in coronary sinus after accessing theright atrium through the jugular vein, and then a cerclage suture ispassed through the proximal septal vein. This cerclage suture can easilypass through right ventricular outflow tract (RVOT), and this inventordefines this technique as “simple mitral cerclage annuloplasty”. Then,the cerclage suture can be easily pulled into the right atrium thusplacing the cerclage suture circumferentially around the mitral annulus.Once positioned, tension is applied to the cerclage suture, therebytightening the mitral valve. This brings together the two lobes of theMV so that they are approximated and reduce the size of its incompleteclosure. This procedure can theoretically obtain very similar results tothose that conventional surgeries can obtain by directly tightening themitral annulus, and shows an immediate reduction of MVR.

However, the cerclage suture passes through the tricuspid valve and theheart, so it may reduce the function of the valve or may damage thevalve and other parts. The inventor has developed a tissue protectiondevice for the coronary sinus and the tricuspid valve and has filed apatent application as a technology for protecting tissues in a body(heart) and it has been registered (Korean Patent No. 10-1116867,registered on Feb. 8, 2012).

DISCLOSURE Technical Problem

The present invention is proposed to improve the technology disclosed inKorean Patent No. 10-1116867 of the inventor and provides a tissueprotection device for mitral valve cerclage annuloplasty, whereby thedevice can protect tissues in the body from a cerclage suture having asimpler structure than the suture used in cerclage annuloplasty.

Technical Solution

In order to achieve the object of the present invention, a tissueprotection device for mitral valve cerclage annuloplasty of the presentinvention is a hollow cylindrical tube where cerclage sutures 10 a and10 b are inserted, in which a hole 22 is formed at a predeterminedportion of the cylindrical tube so that a coronary sinus cerclage suture10 a inserted in a coronary sinus comes out of the cylindrical tube, anda lower section from the hole is inserted into a tricuspid valve toprotect tissues of the tricuspid valve and a ventricular septum.

The cylindrical tube may have: a stem section 23 at an upper portion; asupport section 26 connected to the stem section, having the hole,defined at a predetermined portion over and under the hole, and beingmore rigid than a tricuspid valve insert; and a tricuspid valve insert24 connected to the support section and protecting tissues of thetricuspid valve and the ventricular septum. The tube may be thicker atthe support section than at the tricuspid valve insert.

A protrusion 27 may be formed at a predetermined portion of thecylindrical tube to inform a user of the position of the coronary sinus.

The coronary sinus cerclage suture 10 a and the tricuspid valve cerclagesuture 10 b may be connected to each other, and the coronary sinuscerclage suture 10 a may be formed to be more rigid than the tricuspidvalve cerclage suture 10 b.

A stopper 24 a preventing the cylindrical tube from going deep insidethe myocardium may be formed at a lower end portion of the cylindricaltube, and the stopper 24 a may be a circular protrusion.

The device may become narrower as it goes to an end to cover a cerclagesuture in the ventricular septum.

Advantageous Effects

As described above, the tissue protection device for mitral valvecerclage annuloplasty of the present invention has a simple structurefor protecting the body in mitral valve cerclage annuloplasty performedon a patient with mitral regurgitation, so it is possible to provideconvenience and safety in annuloplasty.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view of the tissue protection devicefor mitral valve cerclage annuloplasty according to an embodiment of thepresent invention.

FIG. 2 is a virtual partial cut view of a heart with the tissueprotection device for mitral valve cerclage annuloplasty according to anembodiment of the present invention.

FIG. 3 is a partial cross-sectional view of the tissue protection devicefor mitral valve cerclage annuloplasty according to an embodiment of thepresent invention.

BEST MODE

Hereinafter, the tissue protection device for mitral valve cerclageannuloplasty of the present invention will be described in detail withreference to the accompanying drawings.

FIG. 1 is a schematic perspective view of the tissue protection devicefor mitral valve cerclage annuloplasty according to an embodiment of thepresent invention and FIG. 2 is a virtual partial cut view of a heartwith the tissue protection device for mitral valve cerclage annuloplastyaccording to an embodiment of the present invention.

A cerclage suture 10, which is a very thin thread having a thickness ofabout 0.014″ and used for mitral cerclage coronary sinus annuloplasty(MVA), was named in the meaning that a piece of string comes out of abody after going around a coronary sinus (CS), a tricuspid valve (TV),and a ventricular septum, and when the cerclage suture comes out of abody, it is divided into two pieces at one end and the other end. Thatis, a cerclage suture is divided into a coronary sinus cerclage suture10 a and a tricuspid valve cerclage suture 10 b in FIG. 1, but it is onecontinuous string making a circle, as shown in the figure. The cerclagesuture may be a string made of synthetic resin such as nylon or ametallic wire (stainless steel or metal coated with nylon). Further, awire formed by twisting a plurality of thin wires may be used. When thecerclage suture 10 is made by twisting a plurality of strings (wires),it is also called a “cerclage rope” or a “cerclage wire” and it is alsoa kind of cerclage suture.

A tissue protection device 20 is a hollow cylindrical tube where thecerclage sutures 10 a and 10 b are inserted. The tissue protectiondevice 20 is a hollow cylindrical tube, that is, it has an empty insideand is manufactured as thick as a 4Fr catheter. The material is a softand flexible rubber or synthetic resin. Alternatively, a metal springcoated with biological synthetic resin may be used.

As for each part of the tissue protection device 20, the device iscomposed of a stem section 23 that is the upper part, a support section26 that is the middle part, and a tricuspid valve insert 24 that is thelower part. The parts collectively make one hollow thin cylindricaltube.

The tissue protection device of the present invention has a hole 22 at apredetermined position and the hole 22 is a part through which thecoronary sinus cerclage suture 10 a inserted in a coronary sinus comesout of the cylindrical tube. The support section 26 is defined topredetermined positions over and under the hole 22, the step section 23is defined over the support section, and the tricuspid valve insert 24for protecting a tricuspid valve and a ventricular septum is definedunder the support section.

The coronary sinus cerclage suture 10 a and the tricuspid valve cerclagesuture 10 b are connected to each other. The cerclage suture 10 a thatis supposed to be inserted into a coronary sinus is not covered with thetube in the coronary sinus, so it may be formed to be more rigid thanthe tricuspid valve cerclage suture 10 b in order to protect thecoronary sinus tissues. The coronary sinus cerclage suture 10 a isformed thicker than the tricuspid valve cerclage suture 10 b and thusdamage to the coronary sinus tissues due to the coronary sinus cerclagesuture is prevented.

The support section 26 where the hole 22 for the coronary sinus cerclagesuture 10 a to come out of the tissue protection device 20 is connectedto the stem section 23 and positioned under the stem section 23.

The support section 26 is formed to be more rigid than the stem section23 or the tricuspid valve insert 24. This is for more stably supportingthe coronary sinus cerclage suture 10 a when the coronary sinus cerclagesuture 10 a comes out of the hole.

FIG. 3 is a partial cross-sectional view of a tissue protection devicefor mitral valve cerclage annuloplasty according to an embodiment of thepresent invention.

As shown in FIG. 3, the support section 26 is thicker than the tricuspidvalve insert 24. That is, since it is preferable that the supportsection 26 is more rigid than the tricuspid valve insert 24, the tube isformed thicker at the support section 26 than at the tricuspid valveinsert 24. In order to make the support section rigid, the outerdiameter of the support section may be increased or the support sectionmay be made of a different material.

The tricuspid valve insert 24 connected to the support section 26 is apart that protects the tricuspid valve and the ventricular septum fromthe cerclage suture 10 b that is inserted in the tricuspid valve.

A stopper 24 a is formed at a lower end portion of the cylindrical tube(that is, a lower end portion of the tricuspid valve insert) to preventthe tissue protection device from going deep inside the myocardium. Thestopper 24 a may be a circular protrusion, as shown in the figure.Further, as shown in the figure, the lower end portion of thecylindrical tube (that is, the lower end portion of the tricuspid valveinsert) may become narrower as it goes to the end in order to cover thecerclage suture 10 b in a ventricular septum.

The distance between an RVOT stopper 24 a and the hole 22 a is selectedin advance such that the tricuspid valve insert 24 is around two timeslonger than the distance between an RVOT exit and the coronary sinushole that is measured from a scanning image of a patient obtained inadvance. That is, the distance between the hole 22 and the stopper 24 ais designed around two times longer than the distance from the stopperto the end. To this end, it may be possible to change the position ofthe stopper at the tricuspid valve insert 24, but various tissueprotection devices having different distances between the hole 22 andthe stopper 24 a may be provided.

When the coronary sinus cerclage suture 10 a coming out of the tissueprotection device 20 is inserted into the coronary sinus, the hole 22 islocked to the edge of a CS inlet. Accordingly, the stopper 24 a of thetricuspid valve insert 24 (RVOT exit stopper) and the hole 22 are fixed,so the tricuspid valve insert 24 is curved into a reverse C-shape aslong as the length without being in contact with the wall of thetricuspid valve (TV). Accordingly, erosion of the tricuspid valve due tothe cerclage suture 10 is prevented and movement of lobes of the mitralvalve is less limited.

On the other hand, a protrusion 27 may be formed on the outer side ofthe tissue protection device 20, as shown in the figure. The protrusion27 prevents the tissue protection device from being excessivelyinserting into the body by locking to a tissue inside the body andsupports a side when the tricuspid valve insert 24 is curved in areverse C-shape.

The embodiments described above are just examples of the presentinvention and the scope of the present invention is not limited to theembodiments. The present invention may be changed, replaced, andmodified in various ways by those skilled in the art without departingfrom the scope of the present invention described in claims.

INDUSTRIAL APPLICABILITY

The present invention can be used for a tissue protection device formitral valve cerclage annuloplasty and, more particularly to a tissueprotection device for protecting tissues of the body (heart) duringmitral valve cerclage annuloplasty that is performed on a mitral valvecerclage patient with mitral regurgitation.

1. A tissue protection device, the tissue protection device comprising:a tube, the tube having a stem section being an upper part, a supportsection being a middle part connected to the stem section, and atricuspid valve insert being a lower part being connected to the supportsection wherein the tricuspid valve insert is configured to traverse atricuspid valve, the tricuspid valve insert having a distal portion, thetricuspid valve insert having a stopper positioned on the distal portionof the tricuspid valve insert to prevent the distal portion of thetricuspid valve insert from going deep inside a myocardium.
 2. Thedevice of claim 1, wherein a hole is formed at the support section. 3.The device of claim 1 further comprising: a first cerclage suture and asecond cerclage suture wherein the first cerclage suture and the secondcerclage suture are connected to each other and inserted in the tube, 4.The device of claim 1, wherein the support section is more rigid thanthe tricuspid valve insert.
 5. The device of claim 1, wherein the tubeis thicker at the support section than the tricuspid valve insert. 6.The device of claim 1, wherein a protrusion is formed at an upperportion of the tricuspid valve insert.
 7. The device of claim 1, whereinthe stopper is a circular protrusion.
 8. The device of claim 1, whereinthe tricuspid valve insert becomes narrower at a lower end portion ofthe tricuspid valve insert.
 9. The device of claim 1, wherein thetricuspid valve insert maintains its C-shape between the hole and thestopper without being in contact with a wall of a tricuspid valve. 10.The device of claim 1, wherein the support section is straight.
 11. Thedevice of claim 1, wherein the stem section is straight.